CEOs are sticking around longer and getting fired less often, new research shows.

The average tenure of Fortune 500 company CEOs rose to 9.7 years in 2013, according to non-profit research firm The Conference Board. That’s the longest average tenure recorded since 2002; the figure had previously been declining for a decade.

In 2000, average CEO tenure was about 10 years, but by 2012 it had dropped to 8.1 years. The authors say the downward trend can be explained by increased competition and intensity in the marketplace – facing more pressure and tougher jobs, CEOs might be less able to withstand a long stint in the top post and leave voluntarily. Private equity firms might also be recruiting away C-level talent, and activist investors might be pushing out CEOs that would have been able to keep their seat in the past.

The authors say last year’s jump in tenure may be connected to CEOs who delayed their retirements in the wake of the downturn, thus extending their time in the top post. The CEOs who did depart in 2013 were older, according to the research – an average of 62.3 years old compared to an average of 60 years old from 2000 to 2013.

In their work, the report’s authors – two Conference Board researchers and an assistant professor at the McDonough School of Business at Georgetown University – also found that fewer CEOs were fired last year. In 2013, 23.8% of CEO turnover was due to dismissals, compared to 24% in 2010 and 25% in 2011. Jason Schloetzer, the Georgetown professor, attributes the decline in ousters to a healthier economy.

“If markets start to decline, I would anticipate an increase in the rate of CEO turnover,” he said, noting that the drop in turnover and increase in tenure would likely reverse if stock prices and earnings performance start trending downward again.

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